Electric circuit breaker



July 22, 1941. E. SCHULZ 2,250,208

ELECTRIC CIRCUIT BREAKER Filed May 29, 1940 2 Sheets-Shae 1 Inventor:Erhard Schulz,

is Attorney- July 22, 1941. E. SCHULZ 2,250,208

ELECTRIC CIRCUIT BREAKER Filed May 29, 1940 2 SheetsSheet 2 ,3 I 22 A g/3 1 M II Inventor:

Erhard Schulz,

is Attorney.

Patented July 22, 1941 UNITED 2,250,208 ELECTRIC CIRCUIT-BREAKER.

Erhard Schulz, Berlin-Steglitz, Germany, assignor to General ElectricCompany, a corporation of New York Application May 29, 1940, Serial No.337,937 In Germany March I, 1939 9 Claims.

My invention relates to electric circuit breakers and more particularlyto those of the airbreak type for high voltage circuits employing apressure jet of suitable arc-extinguishing fluid as the interruptingmeans.

In' electric circuit breakers of the air-break type for outdoor use, itwould be very desirable to remove the contacts and interruptingstructure to as large an extent as possible from the influence of theweather and, furthermore, it would be desirable to mount the entirecircuitinterrupting structure on a single insulator. In the circuitbreakers of the prior art, the construction is usually such that oneportion of the circuit breaker is mounted on one insulator while anotherportion thereof is positioned on another insulator separate from thefirst. Furthermore, prior art devices for outdoor circuit breakeroperation were not arranged so that the contacts and operating partsthereof were relatively free from the influence of the weather.According to my invention, therefore, I provide an electric circuitbreaker of the fluid-blast type for outdoor use wherein the interruptinghead and disconnecting arm thereof are mounted on a common supportinginsulator and the entire structure is so arranged that the interruptinghead specifically as well a the contacts are reasonably protected fromthe weather.

It is an object of my invention, therefore, to provide a new andimproved high voltage cirtected from the influence of the weather.

cuit breaker of the air-blast type which overcomes the disadvantagesabove noted in connection with prior art gas-blast circuit breakers andwhich is efficient in operation and simple in construction.

Further objects and advantages of my invention will become apparent asthe following description proceeds and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming a part of this specification.

The novel features which I believe to be characteristic of my inventionare set forth with particularity in the appended claims. My invention,itself, however, will best be understood by reference to the followingdescription taken in connection with the accompanying drawings in whichFig. 1 represents one embodiment of my invention while Figs. 2 and 3represent certain modifications thereof.

In the arrangement of Fig. 1 of the drawings. I have illustrated myelectric circuit breaker as comprising a single vertical supportingcolumn In which includes an internal stationary or fixed supportinginsulator I I, which may be constructed of any suitable insulatingmaterial, and an external rotatable casing I2 also constructed ofinsulating material and preferably of porcelain. On the stationary orfixed supporting insulator II of the vertically arranged supportingcolumn I0, there is arranged a horizontal arm I3. also of insulatingmaterial, of the same construction as fixed supporting insulator II. Inthe end of horizontal arm I3 is mounted interrupting head I4 arranged ina downwardly projecting direction in such a manner as to be to a largeextent pro- Interrupting head I4 includes a retractable pin I5 having anarcing tip I6 composed of a suitable heat-resisting metal such astungsten, for example. The retractable pin-type contact I5--I6 ismovable longitudinally of and within a fluid chamber I I in the end ofhorizontal insulating arm I3. One end of this chamber I! is provided iwith a restricted throat or nozzle I8 projecting from the under side ofhorizontal arm I3 into which retractable pin I5 extends in thecircuitclosing position. This nozzle or throat I8 is located adjacentthe point of separation of the relatively removable contacts making upthe circuit breaker and incluiding contact I6, as will be described ingreater detail hereinafter.

For the purpose of initially operating retractable pin l5 and contactIS, a piston I 0 connected directly to the retractable pin I5 isprovided. This piston I9 is operable within a cylinder 20 against thebias of a suitable spring 2I. The retractable pin I5, contact I6, pistonI9, cylinder 20, and spring M are combined into one constructional unitfixedly attached to plug 22 which is provided with screw threads so asto cooperate with corresponding threads in horizontal arm I3.Interrupting head I4 comprises the single constructional unit justdescribed. The power supply line 23 is connected to the plug 22 throughsuitable conducting means 24. In order to insure good electricalconnections between retractable pin I5 and cylinder 20, a plurality ofconducting lugs 25 are provided mounted on the interior surface ofcylinder 20 so as to slidingly engage retractable pin I5. Cylinder 20 isalso provided with an opening 26 below piston I9 through which suitablefluid under pressure may be admitted for retracting pin l5 from nozzleI8 against the biasing force of spring 2|. This opening 26 communicateswith chamber II which, in turn, is connected to suitable fluid passagemeans 21 and 21 located within horizontal insulating arm I3 and fixedsupporting insulator II, respectively.

In order to support another contact cooperating with contact I6associated with retractable pin I5, I provide disconnecting arm 28fixedly attached to rotatable casing I2 by means of a sleeve or collar29 which surrounds stationary insulator II and is relatively rotatablewith respect thereto. Power line 30 is electrically connected todisconnecting arm 28 through collar 29. Disconnecting arm 28 is arrangedto pivot when rotatable insulator I2 rotates so as to move in ahorizontal plane parallel with insulating arm I3. Upon the end ofdisconnecting arm 28 adjacent contact I6 is a contact 3I comprising anoblique surface. This oblique contact surface 3I is arranged so that thelower edge 3i there of barely touches contact tip I6 of retractable pinI5 when disconnecting arm 28 is swung under retractable pin I5.Thereafter oblique contact 3| .tends to push contact I6 and retractablepin I5 against the bias of spring 2|, the force of which insures goodelectrical contact. Oblique contact surface 3I, therefore, acts as aguide for the contact tip I6 of interrupting head I4.

The actuating means for rotating casing I2 of supporting column Icomprises the driving device indicated at 32 in Fig. 1, which is operatively connected to a suitable source of gas pressure through theconduit 32. The driving device 32, the details of which are immaterialas far as the present invention is concerned, coacts with the ring gear33 carried by the lower end of rotatable casing I2. Admission of gasunder pressure through the conduit 32 causes rotation of the rotatablecasing I2 and the disconnecting arm 28 as well as retraction ofretractable pin I as will be described in greater detail hereinafter.The single supporting column I 0 of Fig. 1 is illustrated as beingmounted on a transportable base 34 which houses other parts of theswitch drive which are immaterial as far as this invention is concerned.

The operation of my invention as applied to Fig. 1 will be wellunderstood by those skilled in the art but will be briefly describedhereinafter, first with reference to an opening operation of the circuitbreaker. Through suitable means, fluid under pressure is admitted toconduit 32 when it is desired to open the circuit breaker. Thisinitiates a rotation of rotatable casing I2 and disconnecting a m 28through driving device 32 and ring gear 33. At the same time. this fluidunder pressure asses through fluid passa e means 21' and 21 to chamberI'I. Since retractable pin I5 extends into throat or nozzle I8, thefluid under pressure does not readilv escape therethrou h but enterscylinder 20 through opening 26 a ainst the under surface of piston I9.thereby forcing retractable in I5 to be withdrawn from nozzle or throatI8 and causin an arc to be drawn between ohlioue contact surface 3I ondisconnecting arm 28 and contact I6 of interrupting head I4. With thewithdrawal of retractable pin I5 from nozzle I8. a fluid blast isreleased throu h th s nozzle so as to extinguish the are drawn betweencontact I6 and obli ue contact surface 3I of disconnecting arm 28. Bythis time also, disconnecting arm 28 has pivoted sufiiciently so as togreatly increase the arc discharge path. thereby insuring circuitinterruption. The fluid pressure applied to conduit 32 is cut off whenthe circuit breaker is fully open, whereby retractable pin [5 under theforce of spring 2I is again forced into throat or nozzle I8 so as to beready when the circuit breaker is operated to the closed position. Inthe closed position of the circuit breaker, current flows from line 23through the interrupting head I 4 and-disconnecting arm 28 to line 30.

For the closing operation, disconnecting arm 28 is pivoted by rotatingcasing I2 so that the oblique contact surface 3| engages contact tip I6flrst at the narrowest portion 3| thereof and thereafter the obliquecontact surface 3I acts as a guide forcing retractable pin I5 to bewithdrawn slightly within interrupting head ll against the force ofspring 2|, thereby producing a wiping action for good electricalcontact. It will be observed that, with the interrupting head I4 mountedas shown so as to project downwardly, the contact I6 and associatedoperating parts are relatively free from weather as is also the obliquecontact surface 3| of disconnecting arm 28 due to the protection offeredby horizontal arm l3.

Occasionally it is desirable to provide series interruption of thecircuit and, accordingly, in Fig. 2, I have illustrated my invention asapplied to such an arrangement. The corresponding parts of Fig. 2 arecharacterized by the same reference numerals as in Fig. 1. I haveillustrated supporting column III as including a rotatable casing l2mounted on a suitable base 35 which contains the driving apparatus, notshown, for rotating insulator I2. Also mounted on base 35 is a secondconventional supporting column 36 of insulating material supporting aninterrupting head I 4' similar to the interrupting head I! mounted onsupporting column I8, which is identical with the arrangement describedin connection with Fig. 1. Disconnecting arm 28 and collar 29 fixedlyattached to rotatable insulator I2 are similar to the arrangementdisclosed in Fig. 1. Also attached to collar 29, however, isdisconnecting arm 31 which cooperates with interrupting head I 4. Bythis arrangement, a series of interruptions of the circuit are providedwhile, at the same time, providing a large isolation path between therespective contacts in the open-circuit condition.

In Fig. 3, I have illustrated a modification of the arrangement shown inFig. 2 in which simultaneous interruption of the circuit at two pointsis obtained utilizing only a single supporting column Ill. Thecorresponding parts of Fig. 3 are designated by the same referencenumerals as in Fig. 1. Fixed supporting insulator II is. therefore,provided with two horizontal arms I3 and I3 carrying identicalinterrupting heads I4 and I4. Collar 29 supporting disconnecting arm 28is provided with a second disconnecting arm 28 cooperating wtihinterrupting head I4. The operation of the apparatus illustrated in Fig.3 will be understood by those skilled in the art.

Although I have illustrated my invention as applied to a single-phasepower line, it will be understood that it is particularly adaptable tothree-phase construction, in which case, the horizontal arm I3 of thetwo outside phases will be mounted in the same plane but the horizontalarm of the middle phase will be supported in a higher or lowerhorizontal plane so that the disconnecting arms will not interfere withone another.

It will be understood by those skilled in the art that it may beadvantageous to provide an arrangement for the lateral deflection of thegases during circuit interruption in order not to prejudice theefiectiveness of the insulation path etween the interrupting head andground.

While I have shown a particular embodiment of my invention in connectionwith an electric circuit breaker, I do not desire my invention to belimited to the construction shown and described and I intend in theappended claims to cover all modifications within the spirit and scopeof my invention.

What I claim as new and desire to secure by Letters Patent in the UnitedStates is:

1. An electric circuit breaker of the fluid blast type for highvoltagepower circuits comprising a main supporting insulating means, an arcinterrupting unit including contact structure comprising a movablecontact supported by said means, a movable contact structure mounted forrotative movement with respect to said means for engaging said movablecontact of said interrupting unit, and means for directing fluid underpressure to said unit for interrupting arcing upon separation of saidcontact structure.

2. An electric circuit breaker comprising a stationary supporting columnof insulating material including a horizontally projecting arm, a pairof relatively movable contacts .one of which is a retractable pin-typecontact, fluid passage means in said supporting column and ing pivotallymounted with respect to said supprojecting arm having a restrictedexhaust porcasing surrounding saidsupporting column andrigidly attachedto said other contact, said other contact being so constructed andarranged as to engage'said retractable pin-type contact when saidcircuit breaker is in the closed position.

3. An electric circuit breaker comprising a pair of relatively movablecontacts, a stationary supporting insulator having a horizontallyprojecting arm, fluid passage'means in said projecting arm having a.restricted exhaust portion at the lower side of said projecting arm soas to be protected from the weather, one of said contacts being operablewithin said restriotedflig exhaust portion, fluid pressure actuatedmeans connected to said contact for withdrawing the same fromsaidrestricted exhaust portion when fluid is admitted to said fluidpassage means, a rotatable insulating casing surrounding saidfirst-mentioned insulator supporting said other movable contact which isrotatable therewith, and an oblique contacting surface on said. othercontact for engaging with said contact operable in said restrictedexhaust portion of said fluid passage means.

4. In an electric circuit breaker of the fluidblast type, aninterrupting head including a contact movable in a vertical plane, adisconnecting arm cooperating with said contact in said interruptinghead and movable in a horizontal plane, and a supporting means for saidinterrupting head, said disconnecting arm beporting means.

5. In an electric circuit breaker of the fluidblast type, a stationarysupporting column of insulating material including a plurality ofhorizontally projecting arms, an interrupting head mounted in the end ofeach of said horizontally projecting arms, a rotatable casing includinga plurality of disconnecting arms rigidly attached thereto surroundingsaid supporting column, each of said disconnecting arms arranged tocooperate with one of said interrupting heads, and means for operatingsaid circuit breaker so as to obtain a plurality of breaks in theelectrical circuit associated therewith.

6. In an electric circuit breaker of the fluidblast type, a stationarysupporting column of insulating material including a horizontallyprojecting arm, an interrupting head mounted in the end of said arm, arotatable casing including a plurality of disconnecting arms rigidlyattached thereto surrounding said supporting column, one of saiddisconnecting arms arranged to cooperate with said interrupting head,and means for operating said circuit breaker so as to obtain relativemovement between said interrupting head and one. of said disconnectingarms.

7. An electric circuit breaker of the gas blast type comprising asupporting means, relatively movable contact structure including a fixedarc interrupting unit comprising a movable interrupting contactsupported by said means and a coacting movable disconnecting contactmember supported for rotative movement with respect to said means forengaging said interrupting contact, said unit having a gas exhaustopeningv in which the arc is interrupted upon separation of said contactstructure, and means for mounting said interrupting unit with respect tosaid supporting means so that said exhaust opening is substantiallybeneath said unit whereby said contact structure is shielded withrespect to rain and sleet.

8. An electric circuit breaker of the fluid blast type comprising a pairof relatively movable contacts, one of said relatively movable con--tacts being mounted in an interrupting head, a supporting means for saidinterrupting head, the other of said contacts'being carried by adisconnecting arm pivotally mounted with respect to said means, meansfor mounting said interrupting head with respect to said'supportingmeans so that said contacts are located as to be relatively free fromtheweather, and means for obtaining relative motion between said contactsduring the circuit-interrupting opobtaining relative motion between saidcontacts during operation of said electric circuit breaker.

ERHARD SOHULZ.

